Bed motion



1 R.\NCNDD BED MOTION Oct. 5, 1937.

Filed July 8, 1936 5 Sheets-Sheet l INVENTOR JIMES 5? W000 Way 6,1

ATTORNEY$ J. R. WOOD BED MOTION Oct. 5, 1937.

Filed July 8, 1936 3 Sheets-Sheet 2 INVENTOR.

BY JAMES 5. W000 ATTORNEYS J. R. WOOD Oct. 5, 1937.

BED MOTION Filed July 8, 1936 3 Sheets-Sheetj INVENTOR. a/AMES fl? M aaoi ATTORNEYS.

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Patented Oct. 5, 1937 UNITED STATES BED MOTION James R. Wood, Shelton, Conn., assignor to Harris-Seybold-Potter Company, Cleveland, Ohio, a corporation of Delaware Application July 8, 1936, Serial No. 89,615

21 Claims.

This invention relates to improvements in bed reversing mechanism, that is mechanism for reversing the movement of the bed of a fiat bed printing press at the ends of its stroke. In a printing press of this character the reciprocating bed is given a constant speed motion throughout the greater portion of its travel in each direction, but at the two ends of the stroke it is slowed down to a stop and started in the other direction with an accelerating motion. This reversal of motion approximates more or less closely a simple harmonic motion. The present invention has to doprimarily with novel and effective means for imparting such reversing motion to the bed of a flat bed press, although the invention is susceptible of use in connection with other machines in which there are reciprocating parts or parts oscillating about an axis.

One of the objects of the invention is the provision of simple and relatively inexpensive mechanism for the purpose stated, which shall be effective and smooth in operation.

Other objects and features of novelty will appear as I proceed with the description of those embodiments of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which Fig. 1 is an elevational side view showing in a somewhat diagrammatic manner the bed driving mechanism of a flat bed printing press embodying the invention.

Fig. 2 is a detail plan view of the bed rack and driving pinion.

Fig. 3 is a view similar to Fig. 1. but on a smaller scale, showing the mechanismin a position which it occupies during the reversing operation.

Fig. 4 is a view similar to Fig.1 illustrating a modification.

Fig. 5 is a plan view of the bed rack and reversing rack of Fig. 4.

Fig. 6 is a side elevation of still another modification. i

Fig. '7 is a plan view of the bed rack and pinions of Fig. 6, and

Fig. 8 is a vertical cross sectional view taken substantially on the line 8-8 of Fig. l.

Referring first to Figs. 1, 2, 3 and 8, I have shown a shaft I!) to which driving force is delivered by any suitable means. On the shaft Hi there is a gear |2 which meshes with a large gear l3, the latter gear having a diameter preferably three times that of gear l2. The large gear carries a gear segment M with internal gear teeth and a gear segment l5 with external teeth.

Each of these segments occupies an angle of approximately 120, and they are positioned diametrically opposite each other. Internal gear segment I4 is adapted to mesh with a pinion l6, and the external gear segment l5 with a pin- 5 ion These two pinions are keyed to a shaft |8 which extends transversely across the machine and carries about midway between the frame members a pinion l9 which meshes with teeth on the under side of a bed rack 2s. 10

In the machine between the framernembers there is mounted a longitudinally extending guide rail 2| upon which is mounted a slide 2 2 having 7 a vertical guide 23 forming part of .a Scotch yoke construction. The other part of this yoke consistsof a crank roller 2 3 which is journaled upon a disk 25 keyed to shaft ID. The slide 22 therefore is given a simple harmonic motion, and I because of the relation between gears I2 and i3 there are three reciprocations of slide 22 for H each rotation of the large gear l3. Also, since gear I3 makes one revolution for each complete reciprocation of the bed of the press, there are three reciprocations of slide 22 for each reciprocation of the bed. To the forward end of slide 22 there is pivoted a rack 26 having teeth on its upper surfaceadapted to meshwith the teeth of pinion iii. The forward end of this rack runs upon and is supported by azwheel or roller 21, which turns upona shaft 28 that is carried in the free end of a bifurcated link 29 which is pivotally supported at 30 in the frame of the machine. Shaft 28 also carries on opposite sides of wheel 2? two smaller wheels 3| which constitute followers. for a bifurcated cam 32 pivoted at 33 on the frame of the machine. In the position of cam 32 illustrated in Figs. 1 and 8 of the drawings the rack 26 runs upon roller 21 out of contact with pinion I9. When the cam 32 is in the position illustrated in Fig. 3 however the roller 21 holds the reciprocating rack 23 in mesh with pinion l9, and motion is transmitted to the bed 34 of the machine from the reciprocating rack. Cam 32 is formed integral with an arm 35 which extends downwardly below pivot 33 where it is connected with a link 3'E, the opposite end of which is pivotally connected with an arm 31 which swings upon a pivot 38 supported in the frame. The upper end of arm 31 carries a roller follower 39 which runs upon a cam 40 that is keyed to a shaft 4|. Shaft 4| is driven from shaft Ill by means of intermeshing gears 42 and 43 mounted upon those shafts. The gear ratio i uch that gear 4| turns at one-third the speed ing rack 45. 20

of shaft l0, and therefore at the, same rate as gear I3. In other words it makes one revolution for each complete reciprocation of the bed. There are two high spots on cam 40 however, and hence roller 2'! is raised twice for each reciprocation of the bed, the timing being such that this'action occurs at the ends of the bed stroke. One' engagement of therack 26 with pinion 19 occurs while the roller 24 ofthe Scotch yoke is moving from top position to lowermost position, and the other engagement of the rack with the pinion oc curs while the roller 24 is. moving from lower-Y most position up to top position, a fullrotation or shaft l having intervened during which, the rack is out of engagement with the pinion.

' In the form of theinvention illustrated in Figs.

4 and jthere are two racks on the bed of the machine, a constant speed rack 44, and a revers- The pinion l9 meshes'with'the rack 44. Reversing rack 45 meshes continuously with a pinion 46 carried by shaft 41' supported in the machine frame." The reciprocating rack 26 is arranged beneath pinion 46, and is lifted at the proper times to mesh with the pinion in the same manner as, in the previously described form of the invention.

' The modification of Figs. 6 and 7 in a sense combines-certain features of the two previously segment I5 and pinion I1. .45

In thecase of Fig. 4 the described forms, that is to say it employs a separate reversing pinion 48 as in Fig. 4, and a single bed rack as in Fig. 1. The pinion l9 and the pinion 48 are both continuously in mesh with the single bed rack 49.. Pinion 48 is; engaged periodically by reciprocating rack 26 in the same manner as previously described. I z

'0peratzon.The shafts l0 and 4| and the gears 12, Hand 43 rotate continuously'in the direc- .tions indicated by the arrows in Figs. 1 and 4; In

both of these figures the bed is shown moving towardthe right in the constant speed portion of its travel. This constant-speed'motion 'is imparted tothe bed by the rotation of shaft H3 in a clash." Its speed steadily decreases thereafter through the next quarter revolution of shaft H],

reaching zero at the end of the quarter revolution. The following'quarter revolution accelerates the rack 26 from zero speed to maximum speed in the direction toward the right, which likewise re verses the rotation of pinion I9, and likewise the direction of movement of bed 34.' When, roller 24. reaches its top position the rack 26-is lowered,

and at the same time segment [4 comes into mesh with pinion ['6 and the jconstantspeed travel of i the bed; in the direction toward the left is begun. 65-

In the case of Fig. 4, while the reversing action is taking place shaft J8 is slowed down; reversed and accelerated because lof the continuous mesh ing of pinion 19 with bed rack .44, so that when segment l4 comes into meshing position the pinion l 6 is traveling at the same surface speed as segment l4. 'Ihe reversing motion in'Fig. 4 is accomplished in' the samemanner as in Fig. 1, ex-

ceptthat a separate bed rack and pinion 45 and 46 areusedforthe purpose,

When segment l4 goes out of mesh with pinion Hi the bed is 'at the end of the constant speedtraveltoward the left. At this point crank roller 24 is at the top-of its circle of rotationand moving at maximum speed corresponding to the constant speedmotion of the pinion l9. At this point the reciprocating rack 26 is raised into mesh with the pinion. It is moving toward the right at the time. *As the roller 24 moves down clockwise its speedis decelerated, and the'speed of rack 26' V is correspondingly decelerated. At the first quarter position, 90 from the top, the travel of slide 22 and rack 26 is at zero rate, and motion of the rack in the opposite direction begins, thereby reversing the direction of motion of the bed. As

previously stated, each of the segments i4 and i5 occupies an angle of 120. There are two angles of 60 between the segments during which be noted, as of some importance, that the bed is balanced more or less against the slide22 and the rack 26, that is to say at the times of reversal of bed motion the momentum'of the bed is opposed by that of slide 22 and rack 26. This arrange ment assists in cutting down vibration to aminimum.

The operation of the construction illustrated in Figs. 6 and 7 does not differ substantially from that illustrated in Figs. 4 and 5, and further explanation is therefore unnecessary. In both of these cases the drive to the bed at constant speed is difierent from thatof reversal, the pinions 46 and 48 transmitting no force to'the'bed at conthe reversing mechanism functions' It may also stant speed, and the pinions I 9 transmitting none at reversal. is transmitting force to the bed, the other pinion is beingdriven by the bed. In' Fig. l on the other hand the pinion I9 acts to drivethe bed at all times, the shaft l8 being driven by the reversing mechanism as well as by the constant speed mechanism.

Variations from the described structure may be employed. Accordingly I desire it to be under-' When one ofthe pinions l9 and 4S 7 stood that the scope of the invention is to be re-.

garded as defined exclusively by the appended claims rather than by the foregoing description or the accompanying illustration. Having thus described my invention, I claim:

1. In a printing press, a reciprocable form carrier, means for effecting reversal of the movement of the formcarrier at the ends of its strokes comprising teeth on the form carrier, a gear meshing 7 with said teeth, a rack adapted to mesh with said gear, means for reciprocating said rack a plurality of times for each reciprocation oftheform carrier, and means whereby said rack is caused to move transversely into and out of mesh with said gear at the beginning and end of each reversal period. r

2. In a flat bedprinting press, a reciprocating" bed, means for effecting reversal of bed movement at the ends of its travel, comprising a rack on the bed, a gear meshing with said rack, a second rack adapted to mesh with said gear, means for reciprocatin'g said second rack a plurality of times for each reciprocation of the bed, and means whereby said second rack is caused to move transversely into and out of mesh with said gear at the be-:

ginning and end of each reversal period.

3. In aprinting press, a reciprocahle form carrier having intermediate periods ofconstant speed 7 travel, means for effecting reversal of the movement of the form carrier at the ends of its strokes comprising teeth on the form carrier, a gear meshing with said teeth, a cross head, means for reciprocating said cross head a plurality of times for each reciprocation of the form carrier, a rack pivoted to the cross head and adapted to mesh with said gear, and means timed with the reciprocation of said rack for swinging the'latter on its pivot in such manner that it is caused to move into mesh with said gear at the end of each con stant speed travel and out of mesh at the beginning of the next succeeding constant speed travel.

4. In a printing press, a reciprocable form carrier having intermediate periods of constant speed travel, means for effecting reversal of the movement of the form carrier at the ends of its strokes comprising a gear operatively connected with the form carrier, a cross head, means for reciprocating said cross head with simple harmonic motion three times for each reciprocation of the form carrier, the end of each stroke of the form carrier being timed to correspond with the end of a stroke of the cross head, a rack pivoted to the cross head and adapted to mesh with said gear, and means for swinging the rack on its pivot in such manner that his caused to move into mesh with said gear at the end of each constant speed travel of the form carrier and out of mesh at the beginning of the next succeeding constant speed travel.

5. In a printing press, a reciprocable form carrier having intermediate periods of constant speed travel, means for effecting reversal of the movement of the form carrier at the ends of its strokes comprising a'gear operatively connected with the form carrier, at cross head,-means for reciprocating said cross head a plurality of-times for each reciprocation of the form carrier, a rack pivoted to the cross head and adapted to mesh with said gear, a support for said rack, and means for moving said support to swing the rack on its pivot in such manner that it is caused to move into mesh with said gear at the end of each constant speed travel of the form carrier and out of mesh at the beginning of the next succeeding constant speed ravel of the form carrier.

6. In a printing press, a reciprocable form carrier, means foreflecting reversal of the movement of the form carrier at the ends of its strokes comprising a gear operatively connected with the form carrier, a cross head, means for reciprocating said cross head with simple harmonic motion three times for each reciprocation of the form carrier, the end of each stroke of the form carrier being timed to correspond with the end of a stroke of the cross head in the opposite direction, a rack pivoted to the cross head and adapted to mesh with said gear, a support for said rack, and means actuated twice for each reciprocation of the form carrier for moving said support to swing said rack about its pivot into mesh with said gear and to withdraw said support permitting said rack to swing away from mesh with said gear.

7 In mechanism of the class described, the combination with a reciprocating bed, of means for actuating said bed throughout its cycle of movement, said cycle comprising intermediate constant speed periods and two reversal periods, said means comprising a reciprocable rack, means for reciprocating said rack, gearing between said rack and said bed efiective during reversal to actuate said bed upon reciprocation of said rack, and means for causing said rack to be displaced transversely to its pitch line for disengagement from said gearing during the constant speed periods of the cycle of said bed.

8. In mechanismof the class described, the combination with a reciprocating bed, of means for actuating said bed throughout its cycle of movement, said means comprising a reciprocable ment therewith during the reversalof the direction of movement of the bed and away from said gearing for disengagement therefrom during the intermediate travel of the bed. 7

9. In mechanism of the class described, the combination with a reciprocating bed, of means for actuating said bed throughout its cycle of movement, said means comprising a rotatable gear operable to reverse the direction of movement of said bed, a. reciprocable rack adapte-dto mesh with said geanmeans for reciprocating said rack, connections between said means and said rack permitting displacement of the latter toward and away from said gear in a direction transverse to the pitch line of said rack, and'means effective near both ends of the bed travel for moving said rack into mesh with said gear.

10. In mechanism of the class described, the combination with a reciprocating bed, of means for imparting intermediate constant speed travel to the bed in opposite directions andfor reversing the direction of movement of the bed at the ends of its constant speed travel, said means comp-rising a gear for actuating thebed during.

the reversal thereof, a reciprocable rack adapted to mesh with said gear, means for reciprocating 7 said rack, connections between'said last named means and said rack permitting displacement of the latter toward and away from said gear in a direction transverse to the pitch line of said rack, and means effective near both ends of the bed: travel for moving said rack into'mesh with said gear.

combination with a reciprocating bed, of means for actuating said bed throughout its cycle of movement, said means comprising rack teeth carried by said bed, a rotatable gear arranged'to mesh with said rack. teeth, a reciprocable rack adapted to mesh with said gear, means for re ciprocating said rack, and means whereby said line toward said gear forengagement therewith during the end portions of the stroke'of the bed and away from said gear for disengagement therewith during the medial portion of the stroke of the'bed. a 1 a f 12. In mechanism of the class described, a re- 11. In mechanism of the class described, the

' rack is caused to move transversely to its pitch ciprocating bed, a shaft, mechanism associated, therewith for driving said bed at constant speed I through the medial portion of its stroke, said mechanism comprising means for driving said shaft in alternately opposite directions, means for V reversing the direction of movement of said bed at the ends of its stroke comprising a first rack carried by said bed, a gear mounted on said shaft and continuously in mesh with said first rack, a second reciprocable rack adapted to mesh with said gear, means for imparting substantially har ,monic reciprocation to said second rack, and

p rising afirst rack carried by said b ed and a.

gear continuously in mesh with said first rack, jand means for reversing the direction, of movement of'the bed at the ends of its Stroke comprising a second reciprocable rack, means for reciprocating said second rack, and meanswhereby said second rack is caused to move transversely to its pitchline intomesh'with-said gear during the reversal periods and out of mesh therewith during the medial portion of the stroke. V '14. In mechanism of the"class=described, the

combination with a'reciprocating bed, of-means foractuating said bed throughout its cycle of movement, said means comprising a rotatable gear operatively connected with said bed throughoutthe cycle of the latter, a reciprocating member for actuatingsaid bed during the reversal of the movement thereof'at' both. ends of the stroke, a rack .pivota lly' connected to said reciprocating member ahd adapted to mesh with said gear, and I meanswherebysaid rack is caused to move about its pivot transversely to its pitch line to bring said rack into engagement with said rotatable gear during the two reversal periods only.

1 15. In mechanism of the class described, the

combination with a reciprocatingbed, of means o for imparting intermediate constant speedtravel r so tosaid bed in opposite directions and for imparting substantially harmonic reversing motion to said bed at the ends of. itsstroke, said means comprising a rotatable gear operatively connected to said bedthroughout the cycle of the latter, a Scotch yokeda rack pivotally connected to saidScotch yoke for reciprocation thereby, said rack being adaptedjto mesh with said gear, and

meanswherebysaid rack is caused to move about its pivot transversely to itspitch line to bring said rackinto engagement with said gear during both reversal periods, and out'of engagement duringthe intermediate constant speed travel.

16.;In a printing press, a reciprocable form carrier,means for efiecting reversal of the move ment of the form carrier at the ends of its strokes comprising a gear, a rack adapted to mesh with' saidgear, means for reciprocating said rack a plurality of times for eachreciprocation of the form carrier, andfmeans whereby said rack is caused'to move transversely into and out of {mesh withsaid gear at the beginningand end respectively of each reversal period, said form carrier being operatively connected with said'gear so as to be reversed thereby.

l'Zi In afiat bed printing press, a reciprocating bed, means for effectingreversal of bed move- 1 'ment at the ends of itstravel, comprising a rack on the bed, a gear, a second rack adapted to mesh with said gear,means for reciprocating said second rack'a plurality of times for eaclirecip rocation of the bed, and means whereby said second rack" is caused to move transversely into and speed travel, means for effecting reversal of the movement of the form carrier atthe ends of its strokes, comprising a gear, a cross head, means for reciprocating said cross head a plurality of times for each reciprocation of the formcarrier,

arack pivoted; to the cross head and adapted to mesh with'said gear, and means'timed' with the reciprocation, of said rack for swinging the latter onits pivot in such manner that it is caused to move into mesh with said gear at the end of each constant speed travel and out of mesh at the benected with thereby. I

ginning of the:next succeeding constant speed travel, said form carrier being operatively consaid gear so, 'as' to be reversed V 19.. In a' printing press, afeciprocable form;

carrier, means for effecting reversal of movement of the form carrier at the endsof its strokes, comprising a gear;;a;rack adapted to -mesh with said gear, means for reciprocating said rack an odd number of times greater than one for each reciprocation of theform carrier, and means whereby said rack is caused to 'move transversely into and out of mesh with said gear at the beginning and end of each reversal period,- I

20. In a flat bed printing press, a reciprocating ment at the ends of its travel, comprising arack on the bed,-a gear, a second rack adapted to mesh with said gear, means forreciprocating said sec 0nd rack anodd number of times greater than" one for each reciprocation of the bed, and means t r whereby said second rack is caused to move' transversely into and out of mesh with said gear at the beginning and endof each reversal period, said gear and bed rack being operatively connected.

21. In a printing press, a reciprocable formcarrier having intermediate periods of constant speed "travel, means for effecting reversalof movement ofrthe form carrier at the ends of. its strokes comprising a gear, a cross head, means 7 for reciprocating said cross head an odd number 1 bed, means for effecting reversal of bed move.- a

of times 'greater than one for each-reciprocation of the form carrier, a rack' pivoted to the cross head and adapted to :mesh with said gear, means timed with the reciprocation of said rack for swinging the latter on its pivot in such manner e that it iscaused to move into mesh with said gear as it travels'outwardly at the end of each constant speed travel of the bed, and out of mesh as it travels inwardly at thebegilming of the next succeeding constant speed travel of the bed.

JAMES R. LWOOD. 

